PHP Tutorial [us2.php.net]
Working With PHP Datatypes [devpapers.com]
SQL Injection – Public Enemy #1 [php.net]
Arrays in PHP [onlamp.com]
Create Graphics On The Fly [builder.com.com]
PHP Function Reference (Very Useful) [php.net]
Beginner Mistakes [digital-web.com]
Cache Pages, Improve Performance [ilovejackdaniels.com]
PHP Template Engines [whenpenguinsattack.com]
PHP & MySQL Tutorial (And More) [php-mysql-tutorial.com]
Regular Expressions in PHP [weblogtoolscollection.com]